Core Support for five years is requested for the competitive renewal of the Kansas Mental Retardation and Developmental Disabilities Research Center (MRDDRC). The Kansas MRDDRC, now in its 39th year, has played a major international role in generating highly effective behavioral interventions aimed at the causes, prevention, and treatment of mental retardation and related secondary conditions, and in delineating basic knowledge of the underlying biology of typical and atypical development. Since its inception, the center has supported a balanced portfolio of behavioral and biological research. Building on this rich history, a unique contribution of the center in the future will be the development of biologically informed behavioral and pharmacological intervention and treatment approaches. The mission of the Kansas MRDDRC is to support high quality basic and applied research relevant to the causes and prevention of mental retardation and the prevention and remediation of associated secondary conditions and related developmental disabilities. To achieve this mission, the Kansas MRDDRC is designed to accomplish three objectives. First, to develop and support new interdisciplinary basic and applied research initiatives directly relevant to the center's mission, bringing together scientists across the Kansas Center as well as promoting collaborative ventures with researchers at other institutions. Second, to provide cost-effective, scientifically generative, state of the art core services, resources, and facilities that directly enhance the quality and impact of science produced by center investigators and their collaborators. Third, to provide highly efficient, cost-effective systems for planning, developing, managing, coordinating, and disseminating research activities associated with the center. The Kansas MRDDRC's research program is organized around four integrated thematic areas that each reflects a general topic central to MRDD as well as the scientific directions and strengths of our current efforts. These themes are: 1) language, communication, and cognition of mental retardation;2) risk, prevention, and intervention in mental retardation;3) neurobiology of mental retardation;4) cellular and molecular biology of early development. To coordinate and support the research activities of the 76 investigators and 75 research projects associated with these themes, four core units are proposed: a) Communication and Administration;b) Biobehavioral Measurement;c) Research Design and Analysis;d) Integrative Imaging.